Chapter 2 & 8.1 Principles of Ecology & How Organisms Obtain Energy Biology R/Biology Biology...

Chapter 2 & 8.1Chapter 2 & 8.1Principles of Ecology & Principles of Ecology &

How Organisms Obtain EnergyHow Organisms Obtain Energy

Biology R/BiologyBiology R/BiologyBiology AcademicBiology Academic

Mrs. Fournier, Lance, McGraw, Mrs. Fournier, Lance, McGraw, ReissfelderReissfelder

2.1 Organisms and Their 2.1 Organisms and Their RelationshipsRelationships

Main idea – The interactions of biotic and abiotic Main idea – The interactions of biotic and abiotic factors in a community or ecosystem form a tight webfactors in a community or ecosystem form a tight web

ObjectivesObjectives– Describe the difference between abiotic and biotic factorsDescribe the difference between abiotic and biotic factors– Describe the levels of biological organismsDescribe the levels of biological organisms– Differentiate between an organism’s habitat and it’s nicheDifferentiate between an organism’s habitat and it’s niche

Review VocabularyReview Vocabulary– Species: group of organisms that can interbreed and Species: group of organisms that can interbreed and

produce fertile offspring in natureproduce fertile offspring in nature

EcologyEcology

The scientific discipline in which the The scientific discipline in which the relationships among living organisms and relationships among living organisms and the interactions the organisms have with the interactions the organisms have with their environment are studiedtheir environment are studied

In 1866, Ernst Haeckel, German biologist, In 1866, Ernst Haeckel, German biologist, first introduced the study of ecologyfirst introduced the study of ecology

Ecologists are scientists who study ecology, Ecologists are scientists who study ecology, they observe, experiment and model using a they observe, experiment and model using a variety of tools and methodsvariety of tools and methods

The BiosphereThe Biosphere The proportion of Earth The proportion of Earth

that supports lifethat supports life– It extends several It extends several

kilometers above the kilometers above the Earth’s surface into the Earth’s surface into the atmosphereatmosphere

– It extends several It extends several kilometers below the kilometers below the ocean’s surface.ocean’s surface.

– It includes areas such as It includes areas such as the frozen polar regions, the frozen polar regions, deserts, oceans, and deserts, oceans, and rain forestsrain forests

Biotic factorsBiotic factors

The living factors in an organism’s The living factors in an organism’s environmentenvironment

Example Example – All living organisms in the environmentAll living organisms in the environment– All living organisms near the environmentAll living organisms near the environment– All migratory organismsAll migratory organisms

The interactions among organisms are The interactions among organisms are necessary for the health of all species in the necessary for the health of all species in the same geographic locationsame geographic location

Abiotic factorsAbiotic factors The nonliving factors in an organism’s The nonliving factors in an organism’s

environmentenvironment ExamplesExamples

– Temperature rangeTemperature range - Air or water currents- Air or water currents– SunlightSunlight - Soil type - Soil type – Rainfall Rainfall - Nutrients available- Nutrients available– pHpH - Salt Concentration- Salt Concentration

Organisms adapt to survive in the abiotic factors present in their natural environment.

Levels of OrganizationLevels of Organization

The levels increase in complexity as the The levels increase in complexity as the numbers and interactions between numbers and interactions between organisms increase. organisms increase. – OrganismOrganism– PopulationPopulation– Biological CommunityBiological Community– EcosystemEcosystem– BiomeBiome– BiosphereBiosphere

Organism, Population and Organism, Population and Biological CommunitiesBiological Communities

The lowest level of organization is the The lowest level of organization is the individual organismindividual organism

Individual organisms of a single species that Individual organisms of a single species that share the same geographic location at the share the same geographic location at the same time make up a populationsame time make up a population

A biological community is a group of A biological community is a group of interacting populations that occupy the interacting populations that occupy the same time.same time.

Ecosystems, Biomes Ecosystems, Biomes and the Biosphereand the Biosphere

An Ecosystem is a biological community and all of An Ecosystem is a biological community and all of the abiotic factors that affect it. Boundaries of an the abiotic factors that affect it. Boundaries of an ecosystem are flexible and can change, and ecosystem are flexible and can change, and ecosystems might even overlapecosystems might even overlap

A Biome is a large group of ecosystems that share A Biome is a large group of ecosystems that share the same climate and have similar types of the same climate and have similar types of communitiescommunities

All the biomes on Earth combine to form the All the biomes on Earth combine to form the highest level of organization - the biospherehighest level of organization - the biosphere

Ecosystems InteractionsEcosystems Interactions

Interactions between organisms are important in Interactions between organisms are important in an ecosystem.an ecosystem.

A community of organisms increases the chances A community of organisms increases the chances for survival of any one species by using the for survival of any one species by using the available resources in different waysavailable resources in different ways

A habitat is an area where an organism livesA habitat is an area where an organism lives A niche is the role or position that an organism has A niche is the role or position that an organism has

in its environmentin its environment– how it meets its needs for food, shelter and reproductionhow it meets its needs for food, shelter and reproduction– requirements for living space, temperature, moisture, or requirements for living space, temperature, moisture, or

in terms of appropriate mating or reproduction in terms of appropriate mating or reproduction conditionsconditions

Community InteractionsCommunity Interactions

Interactions include competition for basic needs Interactions include competition for basic needs such as food, shelter, and mates, as well as such as food, shelter, and mates, as well as relationships in which organisms depend on each relationships in which organisms depend on each other for survivalother for survival

Competition occurs when more than one organism Competition occurs when more than one organism uses a resource at the same timeuses a resource at the same time

Predation is the act of one organism consuming Predation is the act of one organism consuming another organism for foodanother organism for food– The organism that pursues another organism is the The organism that pursues another organism is the

predatorpredator– The organism that is pursued is the preyThe organism that is pursued is the prey

Symbiotic RelationshipsSymbiotic Relationships

Some species survive due to the Some species survive due to the relationships they have developed with other relationships they have developed with other speciesspecies

Symbiosis is the close relationship that Symbiosis is the close relationship that exists when two or more species live exists when two or more species live togethertogether– MutualismMutualism– CommensalismCommensalism– ParasitismParasitism

MutualismMutualism

The relationship between two or more The relationship between two or more organisms that live closely together and organisms that live closely together and benefit from one anotherbenefit from one another

Lichens on trees is an example of a Lichens on trees is an example of a mutualistic relationship between fungi and mutualistic relationship between fungi and algaealgae

The close association of these two The close association of these two organisms provides two basic needs for the organisms provides two basic needs for the organisms – food and shelterorganisms – food and shelter

CommensalismCommensalism

Is a relationship in which one organism Is a relationship in which one organism benefits and the other is neither helped or benefits and the other is neither helped or harmed.harmed.

ExamplesExamples– Lichens and treesLichens and trees– Clownfishes and sea anemonesClownfishes and sea anemones

ParasitismParasitism

A symbiotic relationship in which one A symbiotic relationship in which one organism benefits at the expense of another organism benefits at the expense of another organismorganism

ExamplesExamples– External – ticks or fleasExternal – ticks or fleas– Internal – bacteria, tapeworms and roundwormsInternal – bacteria, tapeworms and roundworms

2.2 Flow of Energy in an Ecosystem2.2 Flow of Energy in an Ecosystem

Main idea – Autotrophs capture energy, making it Main idea – Autotrophs capture energy, making it available for all members of a food webavailable for all members of a food web

ObjectivesObjectives– Describe the flow of energy through an ecosystemDescribe the flow of energy through an ecosystem– Identify the ultimate energy source for photosynthetic Identify the ultimate energy source for photosynthetic

producersproducers– Describe food chains, food webs, and pyramid modelsDescribe food chains, food webs, and pyramid models

Review VocabularyReview Vocabulary– Energy: the ability to cause change; energy cannot be Energy: the ability to cause change; energy cannot be

created or destroyed, only transformedcreated or destroyed, only transformed

Energy in an EcosystemEnergy in an Ecosystem

One way to study the interactions of One way to study the interactions of organisms within an ecosystem is to follow organisms within an ecosystem is to follow the energy that flows through an ecosystemthe energy that flows through an ecosystem

Organisms differ in how they obtain energy, Organisms differ in how they obtain energy, they are classified as autotrophs or they are classified as autotrophs or heterotrophs based on how they obtain their heterotrophs based on how they obtain their energy in an ecosystemenergy in an ecosystem

AutotrophsAutotrophs

Is an organism that collects energy from Is an organism that collects energy from sunlight or inorganic substances to produce sunlight or inorganic substances to produce foodfood

Green plants and other organisms that Green plants and other organisms that produce their own food are called primary produce their own food are called primary producersproducers

They are the foundation of all ecosystems They are the foundation of all ecosystems because they make energy available for all because they make energy available for all other organisms in an ecosystemother organisms in an ecosystem

HeterotrophsHeterotrophs Is an organism that Is an organism that

gets its energy gets its energy requirements by requirements by consuming other consuming other organismsorganisms

Heterotrophs are also Heterotrophs are also called consumerscalled consumers– HerbivoreHerbivore– CarnivoresCarnivores– OmnivoresOmnivores– DetrivoresDetrivores– DecomposersDecomposers

HeterotrophsHeterotrophs If it eats only plants it is a If it eats only plants it is a

herbivoreherbivore– Cow, rabbit or grasshopperCow, rabbit or grasshopper

If it preys on other heterotrophs it If it preys on other heterotrophs it is a carnivoreis a carnivore– Wolves, lions, and lynxesWolves, lions, and lynxes

If it eats both plants and animals it If it eats both plants and animals it is a omnivoresis a omnivores– Bears, humans and mockingbirdsBears, humans and mockingbirds

Detrivores eat fragments of dead Detrivores eat fragments of dead matter, return nutrients to the soil, matter, return nutrients to the soil, air, and water where the nutrients air, and water where the nutrients can be reused by organismscan be reused by organisms– Worms and many aquatic insectsWorms and many aquatic insects

Decomposers break down dead Decomposers break down dead organisms by releasing digestive organisms by releasing digestive enzymesenzymes– Fungi and bacteriaFungi and bacteria

Models of Energy FlowModels of Energy Flow

Ecologists use food chains and food webs to Ecologists use food chains and food webs to model the energy flow through an ecosystemmodel the energy flow through an ecosystem

Each step in a food chain or food web is called a Each step in a food chain or food web is called a trophic leveltrophic level– Autotrophs make up the first trophic level in all Autotrophs make up the first trophic level in all

ecosystemsecosystems– Heterotrophs make up the remaining levelsHeterotrophs make up the remaining levels

With the exception of the first trophic level, With the exception of the first trophic level, organisms at each trophic level get their energy organisms at each trophic level get their energy from the trophic level before itfrom the trophic level before it

Food ChainsFood Chains A simple model that shows A simple model that shows

how energy flows through an how energy flows through an ecosystemecosystem

Arrows represent the one-Arrows represent the one-way energy flow which way energy flow which typically starts with typically starts with autotrophs and moves to autotrophs and moves to heterotrophsheterotrophs

Each organism uses a Each organism uses a portion of the energy it portion of the energy it obtains from the organism it obtains from the organism it eats for cellular processes to eats for cellular processes to build new cells and tissuesbuild new cells and tissues

The remaining energy is The remaining energy is released into the surrounding released into the surrounding environment and no longer is environment and no longer is available to these organismsavailable to these organisms

Food WebsFood Webs This is a model that This is a model that

represents the many represents the many interconnected food chains interconnected food chains and pathways in which and pathways in which energy flows through a energy flows through a group of organisms. group of organisms.

Feeding relationships Feeding relationships usually are more complex usually are more complex than a single food chain than a single food chain because most organisms because most organisms feed on more than one feed on more than one species.species.

Example – Birds eat a Example – Birds eat a variety of seeds, fruits and variety of seeds, fruits and insectsinsects

Ecological PyramidsEcological Pyramids Below is a diagram that shows the relative Below is a diagram that shows the relative

amounts of energy, biomass or numbers of amounts of energy, biomass or numbers of organisms at each trophic level in an ecosystemorganisms at each trophic level in an ecosystem

Pyramid of EnergyPyramid of Energy Each level represents the amount of energy Each level represents the amount of energy

that is available to that trophic level. that is available to that trophic level. With each step up, there is an energy loss of With each step up, there is an energy loss of

90 percent; available energy decreases90 percent; available energy decreases This energy is used by the organisms for This energy is used by the organisms for

cellular processes and energy is released to cellular processes and energy is released to the environment as heatthe environment as heat

Pyramid of BiomassPyramid of Biomass

Biomass is the total mass of living matter at Biomass is the total mass of living matter at each trophic leveleach trophic level

In a pyramid of biomass, each level In a pyramid of biomass, each level represents the amount of biomass represents the amount of biomass consumed by the level above itconsumed by the level above it

The amount of biomass decreases at each The amount of biomass decreases at each trophic leveltrophic level

Pyramid of NumbersPyramid of Numbers

Each level represents the number of Each level represents the number of individual organisms consumed by the level individual organisms consumed by the level above it; population size decreasesabove it; population size decreases

The relative number of organisms at each The relative number of organisms at each trophic level also decreases because there trophic level also decreases because there is less energy available to support is less energy available to support organismsorganisms

2.3 Cycling of Matter2.3 Cycling of Matter

Main idea – Essential nutrients are cycled through Main idea – Essential nutrients are cycled through biogeochemical processesbiogeochemical processes

ObjectivesObjectives– Describe how nutrients move through the biotic and Describe how nutrients move through the biotic and

abiotic parts of an ecosystemabiotic parts of an ecosystem– Explain the importance of nutrients to living organismsExplain the importance of nutrients to living organisms– Compare the biogeochemical cycles of nutrientsCompare the biogeochemical cycles of nutrients

Review VocabularyReview Vocabulary– Cycle: a series of events that occur in a regular Cycle: a series of events that occur in a regular

repeating pattern repeating pattern

Cycles in the BiosphereCycles in the Biosphere

Energy is transformed into usable forms to Energy is transformed into usable forms to support the functions of an ecosystemsupport the functions of an ecosystem

A constant supply of usable energy for the A constant supply of usable energy for the biosphere is needed, but this is not true of biosphere is needed, but this is not true of mattermatter

The law of conservation of mass states that The law of conservation of mass states that matter is not created or destroyedmatter is not created or destroyed

Natural processes cycle matter through the Natural processes cycle matter through the biospherebiosphere

Matter/NutrientsMatter/Nutrients

MatterMatter– Anything that takes up space and has massAnything that takes up space and has mass– Provides the nutrients needed for organisms to functionProvides the nutrients needed for organisms to function

NutrientsNutrients– A chemical substance that an organism must obtain A chemical substance that an organism must obtain

from its environment to sustain life and undergo life from its environment to sustain life and undergo life processesprocesses

The bodies of all organisms are built from water The bodies of all organisms are built from water and nutrients such as carbon, nitrogen, and and nutrients such as carbon, nitrogen, and phosphorousphosphorous

Biogeochemical CycleBiogeochemical Cycle

The cycling of nutrients in the biosphere The cycling of nutrients in the biosphere involves both matter in living organisms and involves both matter in living organisms and physical processes found in the environmentphysical processes found in the environment

The exchange of matter through the The exchange of matter through the biosphere is called biogeochemical cyclebiosphere is called biogeochemical cycle

These cycles involve living organisms (These cycles involve living organisms (biobio),), Geological processes (Geological processes (geogeo), and chemical ), and chemical

processes (processes (chemicalchemical).).

The Water CycleThe Water Cycle

Evaporation -Evaporation -– Water is constantly evaporating from bodies of waterWater is constantly evaporating from bodies of water– Energy from the Sun heats the liquid water, forming the gaseous Energy from the Sun heats the liquid water, forming the gaseous

form of water called water vaporform of water called water vapor– The water vapor rises and begins to cool in the atmosphereThe water vapor rises and begins to cool in the atmosphere– Clouds form when the cooling water vapor condenses into droplets Clouds form when the cooling water vapor condenses into droplets

around dust particles in the atmospherearound dust particles in the atmosphere


Precipitation –Precipitation –– Water falls from the clouds as precipitationWater falls from the clouds as precipitation– Precipitation transfers water from the Precipitation transfers water from the

atmosphere to Earth’s surfaceatmosphere to Earth’s surface– Precipitation can be in the form of rain, snow, Precipitation can be in the form of rain, snow,

sleet or hailsleet or hail– Precipitation is absorbed by the soilPrecipitation is absorbed by the soil– Percolation of water in soil is transferred into Percolation of water in soil is transferred into

groundwatergroundwater


Groundwater and runoff from land surfaces Groundwater and runoff from land surfaces flow to oceans and other bodies of water flow to oceans and other bodies of water and undergo the process of evaporationand undergo the process of evaporation

Water also evaporates from other sources of Water also evaporates from other sources of moisture, such as water in the soilmoisture, such as water in the soil

Over land, approximately 90% of the water Over land, approximately 90% of the water evaporates, 10% from the surface of plants evaporates, 10% from the surface of plants through a process called transpirationthrough a process called transpiration


Because oceans cover ¾ of Earth’s surface, Because oceans cover ¾ of Earth’s surface, most of the precipitation falls directly into the most of the precipitation falls directly into the ocean.ocean.

Only about 2% of all the freshwater on Earth Only about 2% of all the freshwater on Earth is held in any type of reservoir, such as an is held in any type of reservoir, such as an ice cap, glacier, aquifer, or lake.ice cap, glacier, aquifer, or lake.

The remaining water on Earth circulates The remaining water on Earth circulates through the water cyclethrough the water cycle

The Carbon and Oxygen CyclesThe Carbon and Oxygen Cycles


Carbon and oxygen often make up molecules Carbon and oxygen often make up molecules essential for lifeessential for life

During a process called photosynthesis, green During a process called photosynthesis, green plants and algae convert carbon dioxide and water plants and algae convert carbon dioxide and water into carbohydrates and release oxygen back into into carbohydrates and release oxygen back into the airthe air

These carbohydrates are used as a source of These carbohydrates are used as a source of energy for all organisms in the food webenergy for all organisms in the food web

Carbon dioxide is recycled when autotrophs and Carbon dioxide is recycled when autotrophs and heterorophs release it back into the air during heterorophs release it back into the air during cellular respirationcellular respiration


Carbon and oxygen recycle relatively quickly Carbon and oxygen recycle relatively quickly through living organismsthrough living organisms

Carbon enters a long-term cycle when organic Carbon enters a long-term cycle when organic matter is buried underground and converted to matter is buried underground and converted to peat, coal, oil, or gas depositspeat, coal, oil, or gas deposits

The carbon might remain as fossil fuels for millions The carbon might remain as fossil fuels for millions of yearsof years

Carbon is released from fossil fuels when they are Carbon is released from fossil fuels when they are burned, which adds carbon dioxide to the burned, which adds carbon dioxide to the atmosphereatmosphere


Carbon and oxygen can enter a long-term cycle in Carbon and oxygen can enter a long-term cycle in the form of calcium carbonate, too.the form of calcium carbonate, too.

Calcium carbonate is found in the shells of Calcium carbonate is found in the shells of plankton and animals such as coral, clams, and plankton and animals such as coral, clams, and oystersoysters

These organisms fall to the bottom of the ocean These organisms fall to the bottom of the ocean floor, creating vast deposits of limestone rockfloor, creating vast deposits of limestone rock

Carbon and oxygen remain trapped in these Carbon and oxygen remain trapped in these deposits until erosion processes cause calcium deposits until erosion processes cause calcium and carbon to become part of the short-term cycleand carbon to become part of the short-term cycle

The Nitrogen CycleThe Nitrogen Cycle


Nitrogen is an element that organisms need Nitrogen is an element that organisms need in order to produce proteinsin order to produce proteins

Plants and animals cannot use nitrogen Plants and animals cannot use nitrogen directly from the atmospheredirectly from the atmosphere

Nitrogen gas is captured from the air by Nitrogen gas is captured from the air by species of bacteria that live in water, the species of bacteria that live in water, the soil, or grow on roots of some plantssoil, or grow on roots of some plants


The process of capture and conversion of The process of capture and conversion of nitrogen into a form that is useable by plants nitrogen into a form that is useable by plants is called nitrogen fixationis called nitrogen fixation

Some nitrogen also is fixed during electrical Some nitrogen also is fixed during electrical storms when the energy from lightening storms when the energy from lightening bolts changes nitrogen gas to nitrates.bolts changes nitrogen gas to nitrates.

Nitrogen also is added to soil when chemical Nitrogen also is added to soil when chemical fertilizers are applied to lawns, crops, or fertilizers are applied to lawns, crops, or other areasother areas


Nitrogen enters the food web when plants absorb Nitrogen enters the food web when plants absorb nitrogen compounds from the soil and convert nitrogen compounds from the soil and convert them into proteinsthem into proteins

Consumers get nitrogen by eating plants or Consumers get nitrogen by eating plants or animals that contain nitrogenanimals that contain nitrogen

They reuse the nitrogen and make their own They reuse the nitrogen and make their own proteinsproteins

Because the supply of nitrogen in a food web is Because the supply of nitrogen in a food web is dependent upon the amount of nitrogen that is dependent upon the amount of nitrogen that is fixed, nitrogen often is a factor that limits the fixed, nitrogen often is a factor that limits the growth of producersgrowth of producers


Nitrogen is returned to the soil in several waysNitrogen is returned to the soil in several ways– When an animal urinates, nitrogen returns to the water When an animal urinates, nitrogen returns to the water

or soil and is reused by plantsor soil and is reused by plants– When organisms die, nitrogen returns to the soil when When organisms die, nitrogen returns to the soil when

decomposers break down the dead organisms into the decomposers break down the dead organisms into the nitrogen compound ammonia.nitrogen compound ammonia.

– Organisms in the soil convert ammonia into nitrogen Organisms in the soil convert ammonia into nitrogen compounds that can be used by plantscompounds that can be used by plants

– In a process called dentrification, some soil bacteria In a process called dentrification, some soil bacteria convert fixed nitrogen compounds back into nitrogen convert fixed nitrogen compounds back into nitrogen gas, which returns it to the atmospheregas, which returns it to the atmosphere

The Phosphorous CycleThe Phosphorous Cycle

The Phosphorous CycleThe Phosphorous Cycle

Phosphorus is an element that is essential Phosphorus is an element that is essential for the growth and development of for the growth and development of organismsorganisms

It is found in various compounds of cellsIt is found in various compounds of cells The phosphorous cycle, like the carbon and The phosphorous cycle, like the carbon and

oxygen cycles consists of short-term and oxygen cycles consists of short-term and long-term cycleslong-term cycles

The Phosphorus CycleThe Phosphorus Cycle Short-term cycleShort-term cycle

– Phosphorus is cycled from the soil to producers and Phosphorus is cycled from the soil to producers and then from producers to consumersthen from producers to consumers

– When organisms die or produce waste products, When organisms die or produce waste products, decomposers return the phosphorus to the soil where it decomposers return the phosphorus to the soil where it can be used againcan be used again

Long-term cycleLong-term cycle– Weathering or erosion of rocks that contain phosphorus Weathering or erosion of rocks that contain phosphorus

slowly adds phosphorus to the cycleslowly adds phosphorus to the cycle– Phosphorus, in the form of phosphates, may be present Phosphorus, in the form of phosphates, may be present

only in small amounts in soil and wateronly in small amounts in soil and water Phosphorus often is a factor that limits the growth Phosphorus often is a factor that limits the growth

of producersof producers

Section 8.1 Section 8.1 How Organisms Obtain EnergyHow Organisms Obtain Energy

Main idea – All living organisms use energy Main idea – All living organisms use energy to carry out all biological processesto carry out all biological processes

ObjectivesObjectives– Summarize the two laws of thermodynamicsSummarize the two laws of thermodynamics– Compare and contrast autotrophs and Compare and contrast autotrophs and

heterotrophsheterotrophs– Describe how ATP works in a cellDescribe how ATP works in a cell

Transformation of EnergyTransformation of Energy

All cellular activities require energy; the All cellular activities require energy; the ability to do workability to do work

Thermodynamics is the study of the flow Thermodynamics is the study of the flow and transformation of energy in the universeand transformation of energy in the universe

Laws of ThermodynamicsLaws of Thermodynamics

The 1The 1stst Law – “Law of conservation of Law – “Law of conservation of energy” – Energy can be converted from energy” – Energy can be converted from one form to another, but it cannot be created one form to another, but it cannot be created nor destroyednor destroyed

The 2The 2ndnd Law – Energy that is “lost” is Law – Energy that is “lost” is generally converted to thermal energy – generally converted to thermal energy – “entropy increases”“entropy increases”

Entropy – measure of disorder or unusable Entropy – measure of disorder or unusable energy, in a system.energy, in a system.

Autotrophs & HeterotrophsAutotrophs & Heterotrophs Autotrophs – organisms that make their own foodAutotrophs – organisms that make their own food

– Chemoautotrophs – uses chemicals as a source of Chemoautotrophs – uses chemicals as a source of energyenergy

– Photoautotrophs – convert light energy from the Sun Photoautotrophs – convert light energy from the Sun into chemical energyinto chemical energy

Heterotrophs – organisms that need to ingest food Heterotrophs – organisms that need to ingest food to obtain energyto obtain energy

MetabolismMetabolism All of the chemical reactions in a cell are referred All of the chemical reactions in a cell are referred

to as the cell’s metabolismto as the cell’s metabolism Metabolic pathway is a series of chemical Metabolic pathway is a series of chemical

reactions in which the product of one reaction is reactions in which the product of one reaction is the substrate for the next reactionthe substrate for the next reaction– Catabolic pathwaysCatabolic pathways – releases energy by breaking – releases energy by breaking

down larger molecules into smaller onesdown larger molecules into smaller ones– Anabolic pathwaysAnabolic pathways –uses the energy released by –uses the energy released by

catabolic pathways to build larger molecules from catabolic pathways to build larger molecules from smaller moleculessmaller molecules

The continual flow of energy within an organism is The continual flow of energy within an organism is the result of the relationship of catabolic and the result of the relationship of catabolic and anabolic pathwaysanabolic pathways

PhotosynthesisPhotosynthesis

Photosynthesis is the anabolic pathway in Photosynthesis is the anabolic pathway in which light energy from the Sun is converted which light energy from the Sun is converted to chemical energy for use by the cellto chemical energy for use by the cell

6CO6CO22 + 6H + 6H22O O C C66HH1212OO66 + 6O + 6O22

Cellular RespirationCellular Respiration

Cellular Respiration is the catabolic pathway Cellular Respiration is the catabolic pathway in which organic molecules are broken down in which organic molecules are broken down to release energy for use by the cellsto release energy for use by the cells

CC66HH1212OO6 6 + 6O+ 6O22 6CO 6CO22 + 6H + 6H22O + ATPO + ATP

Photosynthesis & Cellular Photosynthesis & Cellular Respiration Form a CycleRespiration Form a Cycle

ATP: The Unit of Cellular EnergyATP: The Unit of Cellular Energy Adenosine Triphosphate (ATP) is the most Adenosine Triphosphate (ATP) is the most

important biological molecule that provides important biological molecule that provides chemical energychemical energy

ATP is made of an adenine base, a ribose sugar, ATP is made of an adenine base, a ribose sugar, and three phosphate groupsand three phosphate groups

ATP releases energy when the bond between the ATP releases energy when the bond between the second and third phosphate groups is broken, second and third phosphate groups is broken, forming adenosine diphosphate (ADP) and a free forming adenosine diphosphate (ADP) and a free phosphate groupphosphate group

Energy is stored in the phosphate bond formed Energy is stored in the phosphate bond formed when ADP receives a phosphate group and when ADP receives a phosphate group and becomes ATPbecomes ATP

ATP: The Unit of Cellular EnergyATP: The Unit of Cellular Energy

Chapter 2 & 8.1 Principles of Ecology & How Organisms Obtain Energy Biology R/Biology Biology...

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